Space isn’t as empty as you might think;
in between the stars, there’s lots of dust and gas, what’s known as the interstellar medium.
This is the stuff that makes planets and possibly, life.
Most of the interstellar medium is made up of simple atoms, like hydrogen and helium,
but there’s a lot more out there that we’ve never been able to identify.
That is, until the Hubble Space Telescope, that venerable old workhorse, called DIBs.
By DIBs I mean Diffuse Interstellar Bands.
It's a pun.
To get it, it’s probably best if you understand how we figure out what’s floating around out there in space.
Stars give off light. Obviously.
And for that light to reach us, it has to travel through all that dust and gas between the star and us.
When it hits these atoms and molecules, some wavelengths of light get absorbed.
Once the light finally reaches us, we can split it into a spectrum,
and the absorbed wavelengths appear as dim or missing bands.
These bands are like the element’s or compound’s fingerprint.
All we have to do then is match the absorption spectrum to that of known elements or molecules, and bingo,
we’ve got an idea of what’s floating around out there in the beyond.
Well, easier said than done.
Identifying the absorption spectrum of single atoms is a piece of cake,
there’s only so many elements and we can catalogue the patterns they make easily.
But the tricky thing about atoms is that they combine with one another in all sorts of arrangements,
and when they do, the absorption pattern they make gets more complicated.
When we observe starlight, a broad range of colors are missing,
and in patterns unlike any known atoms or molecules on Earth.
These are the Diffuse Interstellar Bands, or DIBs.
There. Now you can go back to the start of the video and laugh.
Masterful joke telling, Julian.
We have spotted over 400 DIBs,
but until recently we haven’t been able to conclusively identify any of them despite decades of trying.
There are just millions of molecules to test them against, it would take lifetimes to go through them all.
Making the task even harder, water vapor in Earth’s atmosphere
can prevent ground-based telescopes from spotting absorption patterns.
That’s where Hubble and a little luck comes into play.
Up above most of the atmosphere, the telescope had an unobstructed view to observe the DIBs.
It peered at blue supergiant stars right along our galactic plane,
where the light would have to travel through the most gas and dust.
Even so, the aging hardware had to be pushed beyond its usual sensitivity limits.
And joy of joys, it actually spotted an absorption pattern scientists recognized.
Hubble picked up the signature of a molecule called C60.
C60 is, as you might have guessed, made up of 60 carbon atoms arranged in a hollow sphere.
It resembles a soccer ball, or the famous geodesic domes of Buckminster Fuller,
so it’s also known as Buckminsterfullerene, or Buckyballs.
C60 has been spotted in space before, but Hubble detected a version of it
that has been ionized by ultraviolet light.
Stripped of an electron, these buckyballs are positively charged so they’re technically C60+,
and this marks the first time they’ve been seen in the interstellar medium.
Confirming C60+ has some interesting implications.
First, it shows just how complex molecules in space can get.
Before C60 was spotted, the next most complex compound was made up of just 12 atoms.
The ionized form of C60 shows that these large molecules
can form even in harsh ultraviolet-irradiated environments.
And the team that found it thinks this points to other large complex carbon-based molecules
that can explain many of the still unidentified DIBs.
This could be a huge clue as to how life itself started.
All life we’ve seen is carbon based
because the element is perfect for bonding with other atoms to make molecules.
If carbon-based molecules can spontaneously occur in the interstellar soup that gives rise to planets,
maybe they’re the seed from which life springs.
Still, there are a lot more DIBs that need explaining,
but thanks to Hubble and some spheres of carbon, we think we’re on the right track.
Buckminsterfullerene has also rarely been spotted here on Earth in rocks,
minerals, and soot from high-temperature combustion.
If you liked this video, check out this video Maren did on schwarzites.
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